(jargon, memory management)   A small piece of data inserted in order to achieve a desired memory alignment or other addressing property.

For example, the PDP-11 Unix linker, in split I&D (instructions and data) mode, inserts a two-byte shim at location 0 in data space so that no data object will have an address of 0 (and be confused with the C null pointer).

See also loose bytes.

[Jargon File]

Last updated: 1994-12-21